// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/socket/socks5_client_socket.h"

#include <algorithm>
#include <iterator>
#include <map>
#include <utility>

#include "base/macros.h"
#include "base/sys_byteorder.h"
#include "net/base/address_list.h"
#include "net/base/test_completion_callback.h"
#include "net/base/winsock_init.h"
#include "net/dns/mock_host_resolver.h"
#include "net/log/net_log.h"
#include "net/log/test_net_log.h"
#include "net/log/test_net_log_entry.h"
#include "net/log/test_net_log_util.h"
#include "net/socket/client_socket_factory.h"
#include "net/socket/socket_test_util.h"
#include "net/socket/tcp_client_socket.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "testing/platform_test.h"

//-----------------------------------------------------------------------------

namespace net {

namespace {

    // Base class to test SOCKS5ClientSocket
    class SOCKS5ClientSocketTest : public PlatformTest {
    public:
        SOCKS5ClientSocketTest();
        // Create a SOCKSClientSocket on top of a MockSocket.
        std::unique_ptr<SOCKS5ClientSocket> BuildMockSocket(
            MockRead reads[],
            size_t reads_count,
            MockWrite writes[],
            size_t writes_count,
            const std::string& hostname,
            int port,
            NetLog* net_log);

        void SetUp() override;

    protected:
        const uint16_t kNwPort;
        TestNetLog net_log_;
        std::unique_ptr<SOCKS5ClientSocket> user_sock_;
        AddressList address_list_;
        // Filled in by BuildMockSocket() and owned by its return value
        // (which |user_sock| is set to).
        StreamSocket* tcp_sock_;
        TestCompletionCallback callback_;
        std::unique_ptr<MockHostResolver> host_resolver_;
        std::unique_ptr<SocketDataProvider> data_;

    private:
        DISALLOW_COPY_AND_ASSIGN(SOCKS5ClientSocketTest);
    };

    SOCKS5ClientSocketTest::SOCKS5ClientSocketTest()
        : kNwPort(base::HostToNet16(80))
        , host_resolver_(new MockHostResolver)
    {
    }

    // Set up platform before every test case
    void SOCKS5ClientSocketTest::SetUp()
    {
        PlatformTest::SetUp();

        // Resolve the "localhost" AddressList used by the TCP connection to connect.
        HostResolver::RequestInfo info(HostPortPair("www.socks-proxy.com", 1080));
        TestCompletionCallback callback;
        int rv = host_resolver_->Resolve(info,
            DEFAULT_PRIORITY,
            &address_list_,
            callback.callback(),
            NULL,
            BoundNetLog());
        ASSERT_EQ(ERR_IO_PENDING, rv);
        rv = callback.WaitForResult();
        ASSERT_EQ(OK, rv);
    }

    std::unique_ptr<SOCKS5ClientSocket> SOCKS5ClientSocketTest::BuildMockSocket(
        MockRead reads[],
        size_t reads_count,
        MockWrite writes[],
        size_t writes_count,
        const std::string& hostname,
        int port,
        NetLog* net_log)
    {
        TestCompletionCallback callback;
        data_.reset(new StaticSocketDataProvider(reads, reads_count,
            writes, writes_count));
        tcp_sock_ = new MockTCPClientSocket(address_list_, net_log, data_.get());

        int rv = tcp_sock_->Connect(callback.callback());
        EXPECT_EQ(ERR_IO_PENDING, rv);
        rv = callback.WaitForResult();
        EXPECT_EQ(OK, rv);
        EXPECT_TRUE(tcp_sock_->IsConnected());

        std::unique_ptr<ClientSocketHandle> connection(new ClientSocketHandle);
        // |connection| takes ownership of |tcp_sock_|, but keep a
        // non-owning pointer to it.
        connection->SetSocket(std::unique_ptr<StreamSocket>(tcp_sock_));
        return std::unique_ptr<SOCKS5ClientSocket>(new SOCKS5ClientSocket(
            std::move(connection),
            HostResolver::RequestInfo(HostPortPair(hostname, port))));
    }

    // Tests a complete SOCKS5 handshake and the disconnection.
    TEST_F(SOCKS5ClientSocketTest, CompleteHandshake)
    {
        const std::string payload_write = "random data";
        const std::string payload_read = "moar random data";

        const char kOkRequest[] = {
            0x05, // Version
            0x01, // Command (CONNECT)
            0x00, // Reserved.
            0x03, // Address type (DOMAINNAME).
            0x09, // Length of domain (9)
            // Domain string:
            'l', 'o', 'c', 'a', 'l', 'h', 'o', 's', 't',
            0x00, 0x50, // 16-bit port (80)
        };

        MockWrite data_writes[] = {
            MockWrite(ASYNC, kSOCKS5GreetRequest, kSOCKS5GreetRequestLength),
            MockWrite(ASYNC, kOkRequest, arraysize(kOkRequest)),
            MockWrite(ASYNC, payload_write.data(), payload_write.size())
        };
        MockRead data_reads[] = {
            MockRead(ASYNC, kSOCKS5GreetResponse, kSOCKS5GreetResponseLength),
            MockRead(ASYNC, kSOCKS5OkResponse, kSOCKS5OkResponseLength),
            MockRead(ASYNC, payload_read.data(), payload_read.size())
        };

        user_sock_ = BuildMockSocket(data_reads, arraysize(data_reads),
            data_writes, arraysize(data_writes),
            "localhost", 80, &net_log_);

        // At this state the TCP connection is completed but not the SOCKS handshake.
        EXPECT_TRUE(tcp_sock_->IsConnected());
        EXPECT_FALSE(user_sock_->IsConnected());

        int rv = user_sock_->Connect(callback_.callback());
        EXPECT_EQ(ERR_IO_PENDING, rv);
        EXPECT_FALSE(user_sock_->IsConnected());

        TestNetLogEntry::List net_log_entries;
        net_log_.GetEntries(&net_log_entries);
        EXPECT_TRUE(LogContainsBeginEvent(net_log_entries, 0,
            NetLog::TYPE_SOCKS5_CONNECT));

        rv = callback_.WaitForResult();

        EXPECT_EQ(OK, rv);
        EXPECT_TRUE(user_sock_->IsConnected());

        net_log_.GetEntries(&net_log_entries);
        EXPECT_TRUE(LogContainsEndEvent(net_log_entries, -1,
            NetLog::TYPE_SOCKS5_CONNECT));

        scoped_refptr<IOBuffer> buffer(new IOBuffer(payload_write.size()));
        memcpy(buffer->data(), payload_write.data(), payload_write.size());
        rv = user_sock_->Write(
            buffer.get(), payload_write.size(), callback_.callback());
        EXPECT_EQ(ERR_IO_PENDING, rv);
        rv = callback_.WaitForResult();
        EXPECT_EQ(static_cast<int>(payload_write.size()), rv);

        buffer = new IOBuffer(payload_read.size());
        rv = user_sock_->Read(buffer.get(), payload_read.size(), callback_.callback());
        EXPECT_EQ(ERR_IO_PENDING, rv);
        rv = callback_.WaitForResult();
        EXPECT_EQ(static_cast<int>(payload_read.size()), rv);
        EXPECT_EQ(payload_read, std::string(buffer->data(), payload_read.size()));

        user_sock_->Disconnect();
        EXPECT_FALSE(tcp_sock_->IsConnected());
        EXPECT_FALSE(user_sock_->IsConnected());
    }

    // Test that you can call Connect() again after having called Disconnect().
    TEST_F(SOCKS5ClientSocketTest, ConnectAndDisconnectTwice)
    {
        const std::string hostname = "my-host-name";
        const char kSOCKS5DomainRequest[] = {
            0x05, // VER
            0x01, // CMD
            0x00, // RSV
            0x03, // ATYPE
        };

        std::string request(kSOCKS5DomainRequest, arraysize(kSOCKS5DomainRequest));
        request.push_back(static_cast<char>(hostname.size()));
        request.append(hostname);
        request.append(reinterpret_cast<const char*>(&kNwPort), sizeof(kNwPort));

        for (int i = 0; i < 2; ++i) {
            MockWrite data_writes[] = {
                MockWrite(SYNCHRONOUS, kSOCKS5GreetRequest, kSOCKS5GreetRequestLength),
                MockWrite(SYNCHRONOUS, request.data(), request.size())
            };
            MockRead data_reads[] = {
                MockRead(SYNCHRONOUS, kSOCKS5GreetResponse, kSOCKS5GreetResponseLength),
                MockRead(SYNCHRONOUS, kSOCKS5OkResponse, kSOCKS5OkResponseLength)
            };

            user_sock_ = BuildMockSocket(data_reads, arraysize(data_reads),
                data_writes, arraysize(data_writes),
                hostname, 80, NULL);

            int rv = user_sock_->Connect(callback_.callback());
            EXPECT_EQ(OK, rv);
            EXPECT_TRUE(user_sock_->IsConnected());

            user_sock_->Disconnect();
            EXPECT_FALSE(user_sock_->IsConnected());
        }
    }

    // Test that we fail trying to connect to a hosname longer than 255 bytes.
    TEST_F(SOCKS5ClientSocketTest, LargeHostNameFails)
    {
        // Create a string of length 256, where each character is 'x'.
        std::string large_host_name;
        std::fill_n(std::back_inserter(large_host_name), 256, 'x');

        // Create a SOCKS socket, with mock transport socket.
        MockWrite data_writes[] = { MockWrite() };
        MockRead data_reads[] = { MockRead() };
        user_sock_ = BuildMockSocket(data_reads, arraysize(data_reads),
            data_writes, arraysize(data_writes),
            large_host_name, 80, NULL);

        // Try to connect -- should fail (without having read/written anything to
        // the transport socket first) because the hostname is too long.
        TestCompletionCallback callback;
        int rv = user_sock_->Connect(callback.callback());
        EXPECT_EQ(ERR_SOCKS_CONNECTION_FAILED, rv);
    }

    TEST_F(SOCKS5ClientSocketTest, PartialReadWrites)
    {
        const std::string hostname = "www.google.com";

        const char kOkRequest[] = {
            0x05, // Version
            0x01, // Command (CONNECT)
            0x00, // Reserved.
            0x03, // Address type (DOMAINNAME).
            0x0E, // Length of domain (14)
            // Domain string:
            'w', 'w', 'w', '.', 'g', 'o', 'o', 'g', 'l', 'e', '.', 'c', 'o', 'm',
            0x00, 0x50, // 16-bit port (80)
        };

        // Test for partial greet request write
        {
            const char partial1[] = { 0x05, 0x01 };
            const char partial2[] = { 0x00 };
            MockWrite data_writes[] = {
                MockWrite(ASYNC, partial1, arraysize(partial1)),
                MockWrite(ASYNC, partial2, arraysize(partial2)),
                MockWrite(ASYNC, kOkRequest, arraysize(kOkRequest))
            };
            MockRead data_reads[] = {
                MockRead(ASYNC, kSOCKS5GreetResponse, kSOCKS5GreetResponseLength),
                MockRead(ASYNC, kSOCKS5OkResponse, kSOCKS5OkResponseLength)
            };
            user_sock_ = BuildMockSocket(data_reads, arraysize(data_reads),
                data_writes, arraysize(data_writes),
                hostname, 80, &net_log_);
            int rv = user_sock_->Connect(callback_.callback());
            EXPECT_EQ(ERR_IO_PENDING, rv);

            TestNetLogEntry::List net_log_entries;
            net_log_.GetEntries(&net_log_entries);
            EXPECT_TRUE(LogContainsBeginEvent(net_log_entries, 0,
                NetLog::TYPE_SOCKS5_CONNECT));

            rv = callback_.WaitForResult();
            EXPECT_EQ(OK, rv);
            EXPECT_TRUE(user_sock_->IsConnected());

            net_log_.GetEntries(&net_log_entries);
            EXPECT_TRUE(LogContainsEndEvent(net_log_entries, -1,
                NetLog::TYPE_SOCKS5_CONNECT));
        }

        // Test for partial greet response read
        {
            const char partial1[] = { 0x05 };
            const char partial2[] = { 0x00 };
            MockWrite data_writes[] = {
                MockWrite(ASYNC, kSOCKS5GreetRequest, kSOCKS5GreetRequestLength),
                MockWrite(ASYNC, kOkRequest, arraysize(kOkRequest))
            };
            MockRead data_reads[] = {
                MockRead(ASYNC, partial1, arraysize(partial1)),
                MockRead(ASYNC, partial2, arraysize(partial2)),
                MockRead(ASYNC, kSOCKS5OkResponse, kSOCKS5OkResponseLength)
            };
            user_sock_ = BuildMockSocket(data_reads, arraysize(data_reads),
                data_writes, arraysize(data_writes),
                hostname, 80, &net_log_);
            int rv = user_sock_->Connect(callback_.callback());
            EXPECT_EQ(ERR_IO_PENDING, rv);

            TestNetLogEntry::List net_log_entries;
            net_log_.GetEntries(&net_log_entries);
            EXPECT_TRUE(LogContainsBeginEvent(net_log_entries, 0,
                NetLog::TYPE_SOCKS5_CONNECT));
            rv = callback_.WaitForResult();
            EXPECT_EQ(OK, rv);
            EXPECT_TRUE(user_sock_->IsConnected());
            net_log_.GetEntries(&net_log_entries);
            EXPECT_TRUE(LogContainsEndEvent(net_log_entries, -1,
                NetLog::TYPE_SOCKS5_CONNECT));
        }

        // Test for partial handshake request write.
        {
            const int kSplitPoint = 3; // Break handshake write into two parts.
            MockWrite data_writes[] = {
                MockWrite(ASYNC, kSOCKS5GreetRequest, kSOCKS5GreetRequestLength),
                MockWrite(ASYNC, kOkRequest, kSplitPoint),
                MockWrite(ASYNC, kOkRequest + kSplitPoint,
                    arraysize(kOkRequest) - kSplitPoint)
            };
            MockRead data_reads[] = {
                MockRead(ASYNC, kSOCKS5GreetResponse, kSOCKS5GreetResponseLength),
                MockRead(ASYNC, kSOCKS5OkResponse, kSOCKS5OkResponseLength)
            };
            user_sock_ = BuildMockSocket(data_reads, arraysize(data_reads),
                data_writes, arraysize(data_writes),
                hostname, 80, &net_log_);
            int rv = user_sock_->Connect(callback_.callback());
            EXPECT_EQ(ERR_IO_PENDING, rv);
            TestNetLogEntry::List net_log_entries;
            net_log_.GetEntries(&net_log_entries);
            EXPECT_TRUE(LogContainsBeginEvent(net_log_entries, 0,
                NetLog::TYPE_SOCKS5_CONNECT));
            rv = callback_.WaitForResult();
            EXPECT_EQ(OK, rv);
            EXPECT_TRUE(user_sock_->IsConnected());
            net_log_.GetEntries(&net_log_entries);
            EXPECT_TRUE(LogContainsEndEvent(net_log_entries, -1,
                NetLog::TYPE_SOCKS5_CONNECT));
        }

        // Test for partial handshake response read
        {
            const int kSplitPoint = 6; // Break the handshake read into two parts.
            MockWrite data_writes[] = {
                MockWrite(ASYNC, kSOCKS5GreetRequest, kSOCKS5GreetRequestLength),
                MockWrite(ASYNC, kOkRequest, arraysize(kOkRequest))
            };
            MockRead data_reads[] = {
                MockRead(ASYNC, kSOCKS5GreetResponse, kSOCKS5GreetResponseLength),
                MockRead(ASYNC, kSOCKS5OkResponse, kSplitPoint),
                MockRead(ASYNC, kSOCKS5OkResponse + kSplitPoint,
                    kSOCKS5OkResponseLength - kSplitPoint)
            };

            user_sock_ = BuildMockSocket(data_reads, arraysize(data_reads),
                data_writes, arraysize(data_writes),
                hostname, 80, &net_log_);
            int rv = user_sock_->Connect(callback_.callback());
            EXPECT_EQ(ERR_IO_PENDING, rv);
            TestNetLogEntry::List net_log_entries;
            net_log_.GetEntries(&net_log_entries);
            EXPECT_TRUE(LogContainsBeginEvent(net_log_entries, 0,
                NetLog::TYPE_SOCKS5_CONNECT));
            rv = callback_.WaitForResult();
            EXPECT_EQ(OK, rv);
            EXPECT_TRUE(user_sock_->IsConnected());
            net_log_.GetEntries(&net_log_entries);
            EXPECT_TRUE(LogContainsEndEvent(net_log_entries, -1,
                NetLog::TYPE_SOCKS5_CONNECT));
        }
    }

} // namespace

} // namespace net
